I'm going to be putting my new PC together soon, and I was going to be buying a new heat sink and a better quality thermal paste in a few months.

I was wondering how risky is it to mess up the CPU if I clean off the stock thermal paste and apply the better quality one?

There's definitely some risk, but it's not too bad.  It all comes down to a crapshoot.

A few years ago I added a NVSilencer to my 6800GT.  I had to remove the old HSF, remove old baked on thermal paste, and put on the new HSF properly.

It all went very smoothly with the appropriate care and research (had to use the right tools for cleaning and application).

Then a week or so ago I take out my 6800GT to dust it, and it dies for no good reason.

Do your best, take your time, and be careful and maybe your CPU won't die on you.

Well, my NVSilencer started performing worse than the default 6800GT HSF after a matter of months.  It was supposed to be QUIETER, and it got quite noisy very quickly.  Right after installation I was about 10 degrees cooler C across the board, but I have no interest in overclocking these days so it never mattered to me.

If you want to overclock, it always seems best to get some different HSF, but if not there's really no reason.  Stock CPU coolers are as quiet as any custom HSF these days, they just don't cool as well.

Viodeo cards react differently than CPU's, its risky because a lot of thermal pastes have metal in them, if you get a little on the wrong places, your bound to have problems.

Cpu;s on the other hand have all of their fragile parts on the bottom, so its a lot less risky.

pretty much what i do is.

1. take off stock heatsink
2. take out CPU
3. take a paper towel and gently wipe off some of the old thermal paste, you dont need to get it all, just the big stuff.
4. take a cotton wipe, dab it in a little bit of rubbing alcohol and clean off the remainder of the CPU. (note, do NOT get anything on the pins of the CPU, dont even touch them, grab the edges of the CPU with your fingers.)
5. Put CPU back in.
6. Take new heatsink, repeat steps 3 and 4 on the heatsink if needed.
7. take 2 pieces of tape and put them both in a parallel position on the CPU, leaving a gap about the width of a toothpick between them.
8. put the thermal paste on the CPU in a line following the tape about an inch and a half long.
9. remove tape (very important step)
10. put new heatsink on evenly.

Dont worry about spreading the thermal paste on the cpu, the pressure from the heatsink will do that for you.

" @Gunner: Using rubbing alchohol is a bit of a bad idea. The ingredients that arent alchohol can be potentially harmful to the computer. Use 100% (99.9% if you wanna be exact) isopropyl alcohol instead. Spray some on a q-tip, paper towel, kleenex, whatever you have and then just use that to gently wipe off the paste. "

I use a really flexible plastic card to remove the grease from the CPU. (like a credit card, but i try and find one more flexible... bus pass, etc)

If you use paper of some sort, make sure you dont leave bits of it behind.

Just be careful and read the directions for the paste carefully. You dont want to use much thermal paste at all. [just follow the directions... its simple... but people get it wrong being all excited and not knowing better].

Also, if the computer is fast already, do you plan on overclocking? If not, just go with the stock cpu cooler, and put the umoney into a better video card.

I would not use tape like the guy above said - tape comes in all sorts of varieties, most that leave byproduct after you remove them, which would burn rather than cool. [some tapes might not leave anything... i dunno]

Just ignore everyone in this thread, and buy Arctic Silver cooling paste, and follow the directions on the arctic silver website. They have directions for different kinds of cpu's.

" I use a really flexible plastic card to remove the grease from the CPU. (like a credit card, but i try and find one more flexible... bus pass, etc) If you use paper of some sort, make sure you dont leave bits of it behind. Just be careful and read the directions for the paste carefully. You dont want to use much thermal paste at all. [just follow the directions... its simple... but people get it wrong being all excited and not knowing better].Also, if the computer is fast already, do you plan on overclocking? If not, just go with the stock cpu cooler, and put the umoney into a better video card.I would not use tape like the guy above said - tape comes in all sorts of varieties, most that leave byproduct after you remove them, which would burn rather than cool. [some tapes might not leave anything... i dunno]Just ignore everyone in this thread, and buy Arctic Silver cooling paste, and follow the directions on the arctic silver website. They have directions for different kinds of cpu's. "

I have done that a tons of times, use 100% rubbing alcholhol only, it won't damage anything that way on the cpu. Then reapply the thermal paste, just a bit then use a cardboard paper to spread it out. It does overflow if you put too much, I know from my mistakes.

"100 percent alcolhol only" trust me, without it, you are putting water on a cpu and using cardboard to scrape it off will ruin it's conductivity of heat to the heat sink.

when wiping anything make sure to use something that wont leave fibers after, I like to use a coffee filter. Make sure not to touch the cpu cleaning it after as you don't wont oil from your skin on it.

"100 percent alcolhol only" trust me, without it, you are putting water on a cpu and using cardboard to scrape it off will ruin it's conductivity of heat to the heat sink. "